A standard unit for measuring carbon footprints. CO₂e accounts for all greenhouse gases by converting their impact into the equivalent amount of carbon dioxide. It allows methane, nitrous oxide, and others to be included in one clear number for easier comparison.
The total amount of greenhouse gases (GHGs) emitted directly or indirectly by an individual, organisation, product, or activity, usually expressed in tonnes of CO₂e.
Gases that trap heat in the atmosphere, contributing to global warming. The main GHGs include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases.
Categories of emissions defined by the Greenhouse Gas Protocol:
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Scope 1: Direct emissions from owned or controlled sources (e.g., company vehicles, fuel combustion)
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Scope 2: Indirect emissions from the generation of purchased electricity, steam, heating, or cooling
Scope 3: All other indirect emissions in a company’s value chain (e.g., employee travel, supply chain, product use)
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The most widely used international accounting tool for understanding, quantifying, and managing GHG emissions
An international standard for quantifying and reporting greenhouse gas emissions and removals at the organisational level. It provides principles and requirements for designing, developing, managing, and reporting GHG inventories.
Achieving a balance between the greenhouse gases put into the atmosphere and those taken out. Organisations typically aim for net zero by reducing emissions and offsetting what remains.
Compensating for emissions by investing in environmental projects that reduce or remove carbon from the atmosphere (e.g., tree planting, renewable energy, carbon capture).
A global body that helps businesses set emissions reduction targets in line with climate science and the goals of the Paris Agreement.
A framework used to evaluate a company's sustainability and ethical impact. Carbon reporting often forms part of the "Environmental" pillar.
The process of measuring and disclosing greenhouse gas emissions, often annually, to comply with regulations, demonstrate transparency, or meet investor requirements.
The method used to quantify and manage GHG emissions. Carbon accounting involves collecting data, applying emission factors, and calculating totals to create a full emissions profile.
A strategy for how an organisation plans to reduce its emissions over time. It may include operational changes, energy efficiency upgrades, transport policies, and supply chain reviews.
A state where net greenhouse gas emissions are zero, usually achieved through a combination of reduction and offsetting. Not as stringent or long-term as "net zero."
A comprehensive list of emission sources and associated quantities of GHGs released over a set period, typically one year.
The year chosen as a reference point for measuring emissions reductions. All future reductions are compared against this year.
A coefficient that converts activity data (like litres of fuel used or kWh consumed) into CO₂e emissions. These are usually provided by regulatory bodies or trusted datasets.
The amount of carbon emitted per unit of output (e.g., per product, per revenue £100k, per employee). Helps compare performance between organisations or years.
A method for defining the organisational boundary for emissions reporting. Emissions are reported from operations over which the company has full authority to introduce and implement policies.
Unintentional releases of gases from equipment or systems, often involving refrigerants or process-related leaks (e.g., HFCs from air conditioning units).
Emissions from the combustion of fuels in fixed equipment, such as boilers or furnaces within buildings or facilities.
Emissions from fuel used in vehicles owned or controlled by the company, including fleet cars, vans, or lorries.
Indirect emissions from energy consumed by the organisation but generated elsewhere (e.g., electricity, heat, or steam supplied by third parties).
Two approaches for calculating electricity-related emissions:
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Location-Based: Uses the average emissions intensity of the local grid
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Market-Based: Uses supplier-specific emission factors (e.g., from renewable energy contracts)
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GHG emissions linked to employee travel that is reimbursed by the company, commonly calculated using distance travelled and fuel type.
Missing or incomplete activity data (e.g., meter readings) that must be estimated using assumptions or historical data.
A method of estimating usage or emissions over a period when full data isn’t available, typically by averaging known values across the time period.
A set of standardised factors provided by the UK Government (DEFRA) to ensure consistency in calculating emissions from common activities in the UK.
A value used to calculate emissions associated with electricity consumption. Represents the average CO₂e emitted per unit of electricity generated by the national grid.
A section of carbon reports used to disclose estimations, approximations, or known data constraints that could affect the accuracy of the emissions inventory.
Total emissions from fuel production, distribution, and final use in a vehicle. Helps compare electric and combustion vehicles more accurately.
The process of defining which sources, activities, and facilities are included in a carbon footprint assessment.
An external, third-party declaration confirming that a GHG inventory has been reviewed and meets recognised standards.
A framework for disclosing climate-related risks and opportunities that affect financial performance
Emissions originating from biological sources such as plant or animal matter, often treated separately from fossil fuel emissions.
A planned sequence of emissions reduction steps to achieve long-term climate targets, such as net zero.
Emissions that remain after all feasible reduction measures have been implemented and which typically require offsetting.
The total amount of CO₂e that can be emitted over a period to stay within a specified climate target (e.g., 1.5°C warming).
A defined level under which emissions or data are considered too small to significantly impact reporting results or decisions.
When emissions reductions in one area indirectly cause increases elsewhere, often due to relocation of production.
Emissions associated with the production and delivery of goods or services prior to their use by the organisation.
Emissions generated after a product or service leaves the organisation’s control (e.g., product use, disposal).
Documentation (such as REGO in the UK) that verifies the renewable source of purchased electricity.
A state in which all climate impacts (not just CO₂) are balanced, including warming and potential cooling effects.
A measurable goal to reduce emissions in line with the level of decarbonisation required to meet the Paris Agreement goals.